I suppose it is physically possible to get really good really fast. Given the bell curve there will be some people who are naturally good at sports and pick everything up quickly. I think the main reason that members have trouble with this claim is that we see it so often. And generally when we start digging for details the claim turns out to be, um, stretched a bit. The real problem is that evaluating yourself is very difficult. I'm new enough to snowboarding that I still clearly remember my first days on the slopes. I really thought I was doing great and I wondered what all the fuss was about. Now looking back, I was maybe progressing faster than average but I was still going through the normal learning curve. I also did a black diamond run in my first week, but again, looking back I didn't do it right.
Well for what it's worth, I did progress a lot faster than most of my friends even though some of them do summer sports and work out regularly while I didn't. Most of my friends can't actually do the double diamonds and when I "took them", it took really long for them to "survive" and get down, and that was pretty much the end of thier day after that beating.
And when I got on my friend's unicycle on the first time, he did say that my balance was "incredible". But my ninja skillz aren't exactly the point here.
I'm just using that example to indicate that learning to ride switch can be pretty hard...even much harder than your normal direction. But of course, everyone falls on the "bell curve" somewhere for any activity.